308 MORPHOLOGY AND EVOLUTION
Nerve to Pyriformis (Pyi1-).
Chimpanzee: S2 (Hepburn,Ghampneys, Sonntag). Gorilla: L-S.C.% SI (Hepburn). Orang: L-S.C., SI (Hepburn). Gibbon:------
Nerve to Quadratus Femoris (Q.F.;.
Chimpanzee : Tibial (Bolk) ; Great Sciatic
(Sonntag). Gorilla : As in Man. Orang: As in Man. Gibbon: As in Man.
Nerve to Gemelli (G.N.).
Chimpanzee: S13 S2 (Hepburn); 82 (Sonntag). Gorilla: 81, S3. Orang: SI, 82. Gibbon: SI, 82.
The ilio-inguinal, ilio-hypogastrie and genito-croral nerves are distributed as in Man. The lateral cutaneous nerve supplies the skin of the outer surface of the thigh by several branches.
The anterior crural (femoral) nerve supplies the iliacus within the pelvis. In the thigh in the Chimpanzee it divides into anterior and posterior branches. The former supplies the sartorius, pectineus and gracilis and gives off the patellar and saphenous cutaneous nerves. The latter supplies the quadriceps extensor muscle.
The obturator nerve in the Chimpanzee divides into inner and outer parts, which emerge at the sides of the superficial head of the adductor brevis (fig. 36). The former supplies the pectineus, gracilis, adductor longus and adductor brevis. The latter supplies the obturator
externus, adductor brevis and the whole of the adductor
* L-S.C. --- lurabo-sacral cord*